1. Field of the Invention
The present invention relates to a control system for an internal combustion engine and, particularly, to a control system that performs control according to an ignition timing of fuel supplied to the internal combustion engine.
2. Description of the Related Art
Japanese Patent Laid-open No. JP2004-100566 discloses a fuel injection control apparatus in which the cylinder pressure (i.e., pressure in the combustion chamber) is detected by a cylinder pressure sensor. A fuel injection amount, a fuel injection timing, and the like are controlled according to the detected cylinder pressure. According to the disclosed fuel injection control apparatus, a crank angle Cmax, wherein the cylinder pressure has reached a maximum value, is detected, and the fuel injection timing is corrected so that the detected crank angle Cmax coincides with the target value which is previously set according to the engine operating condition.
The cetane number of fuels distributed in the market varies in the range from “40” to “60”. Therefore, it is preferable to perform control suitable for the cetane number of the fuel being used by using a plurality of control maps corresponding to the plurality of cetane numbers of the fuels in the market. Under such control, the fuel injection control is more suitably adapted to the fuel being used as the number of control maps used increases.
However, if the number of control maps used increases too much, the problem of the amount of manpower necessary for setting the control maps increases and/or the memory capacity needed for storing the control maps increases.